Tubular-fork crown.



No. 649,633. Patented May l5, I900.

W. H. FAUBER.

TUBULAR FORK BROWN.

(Application file'd Oct. 17, 189B.)

(No Model.)

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PATENT WILLIAM II. FAUBER, on CHICAGO, ILLINoIs.

TUBULAR-FORK CROWN.

bPECIFIGATION forming part of Letters Patent No. 649,633, dated May 15,1900.

Application filed October 17, 1898.

{1 0 Ml whom it may concern.-

Be it known that I, WILLIAM H. FAUBER, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Tubular-Fork Crowns; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to an improved c011- struction in forks forbicycle-frames and like tubular structures.

The invention is more especially applicable to the construction of forksfor bicycles of that kind which are joined to the hanger or other partof the bicycle-frame by a single frame member-such as the rear fork,which is attached to the hanger-sleeve, or the rear stay-fork, which isattached to the seat-post fitting by a single tube or member and forkedat its rear lower ends to form the rear stayarms.

A fork embodying my invention consists generally of two tubes which arearranged side by side and are long enough to form both the fork sides orarms and a portion of the shank or body of the fork, each tube formingone fork-arm and one-half or a portion of one-half of the shank, and-atube or thimble which fits at one end over the shank portions of thetubes and is permanently attached thereto and is adapted to engage atits other end a thimble on the crank-hanger, seat-post fitting, or otherpart of the bicycle and forms in connection with the adjacent ends ofsaid fork-tubes the shank of the fork. The said fork-tubes are providedbetween their ends with double bends by which the parts forming theshank are offset from the parts forming the arms, and the said offsetparts are secured to each other side by side, so that they together forma single tubular shank of double structure. Over said offset portions ofsaid tubes is fitted the sleeve or tubular sec tions, which form, inconnection with said olfset portions of the tubes, the shank of thefork, said sleeve or tubular section being permanently secured to thefork members by brazing or otherwise and having at its end adjacent tothe fork-arms tongues which are Serial No. 693,756. (No model.)

bent over and embrace the joint between the parts which form the arms. V

The invention consists in the matters hereinafter set forth, and moreparticularly pointed out in the appended claims.

In the drawings, Figure 1 is a view, partly in plan and partly insection, of a fork constructed in accordance with my invention. Fig. 2is a side elevation of one of the ofiset tubes from which a forkembodying my invention is made. Fig. 3 is a plan view of the two forkmembers after they have been bent to form the offset and ready to beinserted into the shank-sleeve. Figs. iand 5 are two views of theshank-sleeve. Fig. 6 is a cross-section taken on line 6 6 of Fig. 2.Fig. 7 is acrosssection taken on line 7 7 of Fig. 3. Fig. 8 is afragmentary elevation of the parts of the junction of the shank and forkmembers.

9 is an end view of the shank-sleeve.

As shown in the drawings, A A indicate fork arms or sides, A A theportions of said tubes which together constitute a portion of thefork-shank, and 13 a tubular section or sleeve which forms with saidparts A the completed fork-shank and which is adapted for engagement atits outer end with a thinnble on the part to which the fork is to beconnected. The tubes forming the fork sidesA A and the shank portions AA are provided between their ends with double or reverse bends, as shownat Ct a, and each is provided in the part thereof which forms a portionof the shank with a fiat face a, adapted for contact with thecorresponding fiat face of the other tube in such manner as to give acylindric or other symmetrical exterior form to the shank portion, saidshank being cylindrical, as herein shown. The cylindric section orsleeve I3 is made of approximately the same or slightly-greater internaldiameter than the external diameter of the shank portions A the partsare assembled, so as to form a rigid connection between the same.

In order to more firmly join the shanksleeve B to the fork-tubes, saidsleeve is provided in its end adjacent to said fork-tubes with one ormore inwardly-directed extensions b,which when the sleeve has beenslipped over the shank portions A of the fork-tubes in assembling theparts extend inwardly beyond the offset or shank portions and betweenthe side or fork-arms in their parts adjacent to the junction of thesame with the shank. Said extensions are adapted to be folded at theirextreme ends over the inner curved surface at the offset portion of bothfork-arms, so as to cover the meeting edges of said shank portions A,and are brazed or otherwise permanentlysecured thereto. Preferably twoof said extensions 1) will be provided, one on each side of said sleeveB, and said extensions will extend over and cover the meeting edges ofsaid shank portions both above and below the same. Said extensions will,moreover, be made of such length as to meet or overlap at their innerends when folded to their final positions. As a preferable manner ofaccomplishing this result the said sleeve-shank B, which is made from astraight cylindric tube, is provided in one end thereof ondiametrically-opposite sides with cut-away portions or notches Z), saidnotches being of such size and shape as to make the rearwardly-direotedextension I) on the sides of said tubes of considerable width and inposition at right angles to said notches. The inner edges of saidnotches will be preferably made of such shape as to conform to the outercurved surfaces of the fork-tubes in their parts adjacent to the shankportions A, so that when the parts are assembled, as shown in Figs. 1and 8, a close fit will be formed be tween said curved inner edges ofthe notches and the exterior curved surfaces of the forkarms. Saidextension I) of the sleeve will preferably be made of such length thatwhen folded together they will meet midway between the sides of the forkand will be made of such shape at their meeting ends as to form a flushjoint or connection, as shown in Fig. 7. The extensions 1), as well asthe sleeve, will be brazed to or otherwise permanently united with thefork members, so that a rigid connection is formed between the same.

In giving shape to the end of the sleeve 13, I prefer to employ acutting-tool the radius of which corresponds with that of the curvedportions of the fork-arms and having cutting edges shaped to conform tothe cross-sectional shape of the outer surfaces of the fork-arms, sothat the notches formed by the cutter, as seen in Eigs. 5 and 9, willconform exactly to the exterior shape of the fork-arms, while at thesame time sharp or feathered edges will be formed at either side of theextensions 1), as clearly seen in Fig. 9. When the sleeve thus made isplaced over the shank portions of the fork-arms, the portions of saidshank between the projections b will fit accurately and closely aroundthe outer surface of the fork-arms adjacent to the bends therein ,whilethe sharp or feathered edges of the projections 1) will meet the sidefaces of the said fork-arms and leave no abrupt surface or shoulders atthe sides of said projection. Moreover, when the extremities of theoverlapping portions or extensions 1) are bent into their finalpositions against the inner surfaces of the fork-arms, as shown in Figs.7 and 8, the'sharp or feathered edges thereof will come in contact withsuch inner surfaces, so that the said extensions will present smooth androunded surfaces without any shoulders at their side edges and havingconvexly-rounded outer faces corresponding with the original curvatureof the tube forming the shank, as clearly seen in Fig. 8.

In the manufacture of a fork made as described the tubes constitutingthe fork-arms will be made from tubular blanks, which will be suitablybent and flattened in their shank portions to give the desired shape,and said tubes will preferably be tapered, as herein shown, in order toafford desirably-proportioned diameters at the shank and arm portions ofthe fork.

The fork herein shown and described may be made and sold independentlyas an article of manufacture, and the outer end of the shank-sleeve Bwhen the manufacturer is assembling the frames will be cut away toprovide the desired length in the shank. If found desirable, the shankportions A of the fork members may be extended throughout the greaterportion of the length of the sleeve 13, so as to abut against thethimble of the part to which the fork is to be attached. Owing to theoverlapping construction between the sleeve and the fork members,however, such extension of the shank portions A of the forktubes willnot be necessary, thereby enabling the fork as a whole to be lightened,if desired, by making the shank portion relatively short, while at thesame time affording a strong and rigid construction.

Fork crowns have heretofore been constructed of drop-forgings orcastings joined by brazed joints to the fork-arms and forkshank; butcrowns thus constructed have the disadvantage of having many joints, ofbeing unduly heavy, and of being expensive to finish, because requiringthe grinding and polishing of all the surfaces of the casting or forgingforming the crown after the brazing is completed. Fork-crowns have alsobeen made by bending in semicircular form the middle part of a tubewhich constitutes both of the fork-arms and then attaching to thecentral part of the curved part a tubular shank by means of outwardlyextending flanges formed on the end of the shank, which flanges overlapand are fitted to the adjacent surface ofthe crown and secured theretoby brazing. This construction has the disadvantage of necessarilypresenting abrupt edges or shoulders around the margins of the flange,thereby making the Work of grinding and finishing the parts bothdifficult and expensive. I

ICS

Moreover, in such prior construction there are no interfitting partstending to maintain the fork-arms accurately in position with respect tothe shank, so that much care is required to insure the holding of theparts in their proper relative positions during the brazing operation.

A principal advantage arising from the novel construction hereindescribed is that the parts when assembled are brought and held firmlyin proper relative position by the construction and formation of theparts, it being obvious that when the shank portions of the fork-armsare inserted in the sleeve B and the extensions 5 are bent downwardlyover or around the said fork-arms the parts will be rigidly and stronglyheld exactly in their proper positions even before the brazing isaccomplished, and no special means, such as riveting or wiring, isrequired for this purpose. The employment of the extensions 17, arrangedas described, is of very great importance and secures importantadvantages for the reason that said extensions when secured by brazingto the fork members at both sides of the line of juncture between themform stays which serve to resist strains tending to spread apart thefork arms, as well as to greatly stiffen and strengthen the structure asa whole. Moreover, it is found that in the act of bending the fork-armsto form the offset portions the metal is made thinner and thereforesomewhat weakened, especially at the abrupt bends, where the flattenedpor tions of the shanks join the curved inner surface of the fork-arms,and it will be apparent that the extensions 1) when brazed to thesurfaces beneath them constitute reinforcements of the metal of thefork-arms at these points, said extensions, in fact, overlapping theadjacent parts of the fork-arms and extending over the same to pointsoutside of the angles or bends referred to, so that said extensionsserve to strengthen and stiffen the fork-arms for some distanceoutwardly on either side of the bends referred to. The employment ofsaid extensions therefore gives to a forkcrown made in two pieces agreat degree of strength and stiffness at the point at which the twoparts forming the fork-crown are joined to each other.

A fork constructed as above described has the advantage of being easilyand cheaply made, while at the same time it possesses great strength byreason of the fact that the two pieces which form the shank or bodyportion and the fork sides are continuous or made in one piece andwithout joints. The making of the shanks from the joined end portions ofthe tubes flattened at their meeting faces in the manner described hasthe advantage of making the shank portion exceedingly strong andrigid,the same being stronger than a single tube of the same size byreason of the double transverse wall formed by the flattened sides ofthe two tubes.

A further and important advantage gained by the use of the shank-sleeveB, provided with the forwardly-extending projections I), is that thejoint between the meeting edges of the tubes at the shank or oifsetportions is covered by said projections and the appearance of the forkas a whole thereby greatly improved. In the practical manufacture of afork of this general character from sheet metal it is not usuallypracticable or desirable to make sharp or angular bends Where the flatparts join the convex or rounded part of the fork-shanks, so that agroove or depression is formed along the meeting surfaces of the twotubes which requires the use of solder or filling material to give asmooth or continuous surface at the sides of the joined shank portions.Moreover, the joint at the inner side of the fork cannot be so made asto provide a continuous curved surface from one fork to the otherwithout the use of filling material in the groove or depres-' sionreferred to. In the present construction, however, this part of the forkis completely covered by the extensions 1) of the shank-sleeve, so thatthe grooves referred to are entirely concealed and a desirably smoothand finished appearance given thereto.

1 claim as my invention 1. A tubular fork consisting of two tubes bentto form the fork-crown and having offset parts which are bent at anangle to the main parts of the tubes and which are fiattened on theirinner or contact faces and together form a cylindric shank, a sleeveprovided at its inner end with two extensions and which surrounds saidshank with its edges between said extensions abutting against the outersurface of the crown at either side of said offset parts, saidextensions being bent around the adjacent parts of both tubes Where thelatter meet at the center of the crown.

2. A tubular fork consisting of two tubes bent to form the fork-crownand having offset parts which are flattened on their inner or contactsurfaces and together form a cylindric shank, a sleeve surrounding saidshank and provided at its inner end on opposite sides thereof withtongues which are folded over the angular parts of the tubes where thelatter are joined at the center of the crown and meet end to end betweenthe side faces of said crown.

3. A tubular fork consisting of two tubes bent to form the fork-crownand having offset parts, which are flattened on their inner or contactsurfaces to form a cylindric shank, a sleeve surrounding said shank andprovided at its inner end on opposite sides thereof with notches curvedto fit the curved outer surfaces of the crown and provided between saidnotches With'extensions which are folded over the angular parts of saidtubes where the latter meet at the center of the crown.

4. A tubular fork consisting of two tubes bent to form the fork-crownand having off- 4; ea es r 10 parts of the tubes, Where the latter meetat the center of the crown with their flat faces in contact with saidtubes.

In testimony that I claim the foregoing as my invention I affix mysignature, in presence of two Witnesses, this 24th day of September, 15

A. D. 1898. I

WILLIAM H. FAUBER. Witnesses:

WILLIAM L. HALL, CHARLES W. HILLS;

